The Bashkirian is in the International Commission on Stratigraphy geologic timescale the lowest stage or oldest age of the Pennsylvanian . The Bashkirian age lasted from 323.2 to 315.2 Ma , is preceded by the Serpukhovian and is followed by the Moscovian .
6-678: The Bashkirian overlaps with the upper part of the Namurian and lower part of the Westphalian stages from regional European stratigraphy. It also overlaps with the North American Morrowan and Atokan stages and the Chinese Luosuan and lower Huashibanian stages. The Bashkirian was named after Bashkiria, the then Russian name of the republic of Bashkortostan in the southern Ural Mountains of Russia , home of
12-619: Is a subdivision of the Carboniferous system or period , as well as the regional Silesian series . The Namurian is named for the Belgian city and province of Namur where strata of this age occur (part of the Belgian Coal Measures ). The Millstone Grit Group in the lithostratigraphy of northern England and parts of Wales is also of Namurian age. The Namurian age lasted from 331 to 319 million years ago. It
18-669: Is preceded by the Visean stage/age (which corresponds to the upper Carboniferous Limestone of Great Britain) and succeeded by the Westphalian stage/age (which corresponds to the lower and middle Coal Measures of Great Britain). In the official geologic timescale of the International Commission on Stratigraphy (ICS), the Namurian straddles the boundary between the Mississippian subperiod (359-323 Ma) and
24-640: The Bashkir people . The stage was introduced by Russian stratigrapher Sofia Semikhatova in 1934. The base of the Bashkirian is at the first appearance of conodont species Declinognathodus noduliferus . The top of the stage (the base of the Moscovian) is at the first appearance of the conodonts Declinognathodus donetzianus or Idiognathoides postsulcatus , or at the first appearance of fusulinid Aljutovella aljutovica . The GSSP ( type location for
30-495: The Pennsylvanian subperiod (323-299 Ma). The upper part of the (regionally defined) Namurian stage corresponds to the (internationally used) Bashkirian stage whilst the lower part is assigned to the preceding Serpukhovian stage. Frequent references appear in scientific literature to a Namurian epoch or Namurian series , reflecting the stage's earlier status. Substages, from youngest to oldest: The boundary between
36-542: The base of a stage) for the Bashkirian is in the Battleship Wash Formation at Arrow Canyon, Nevada . The Bashkirian contains six biozones based on conodont index fossils : 36°44′00″N 114°46′40″W / 36.7333°N 114.7778°W / 36.7333; -114.7778 Namurian The Namurian is a stage in the regional stratigraphy of northwest Europe, with an age between roughly 331 and 319 Ma (million years ago) . It
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